In production of semiconductor devices such as microprocessors, memories and CCD and flat panel display devices such as TFT liquid crystal, pattern formation and thin film formation are carried out at a level of from submicron to sub-0.1 μm on the surface of a substrate of e.g. silicon, silicon oxide (SiO2) or glass, and it has been an extremely important issue to reduce a very small amount of contamination on the substrate surface in each step in production. Among contaminations of the substrate surface, particularly particle contamination, organic contamination and metal contamination decrease electric characteristics and yield of devices, whereby they have to be reduced as far as possible before the next step is carried out. For removal of the contamination, cleaning of the substrate surface by means of a cleaning solution is commonly carried out. For the cleaning, it is required to highly clean the surface without any adverse effect in a short time with high reproducibility at a low cost. The level of these requirements is increasingly strict along with high integration and price-reduction of devices in recent years.
In production of semiconductor devices in recent years, a new metal material (such as Cu) having a low resistance as a wiring and a low dielectric constant (Low-k) material as an interlayer dielectric film are becoming introduced to achieve an increase in the speed and high integration of devices. Further, for formation of a wiring, application of CMP (chemical mechanical polishing) technique is in progress. For cleaning between steps, conventional RCA clean employing a mixture of an acidic or alkaline solution with hydrogen peroxide can not be employed since a wiring material will be corroded. Further, many of low dielectric constant insulating films have a hydrophobic surface, repel the cleaning solution and are thereby hardly cleaned. Further, cleaning after the CMP step is problematic in that a slurry (abrasive grains) to be used for CPM will contaminate the wiring or the low dielectric constant insulating film surface. To dissolve these problems, application of various cleaning technique has been attempted.
For example, a cleaning solution containing a surfactant having a specific structure, capable of removing particle contamination and metal contamination without corroding a transition metal on the surface, has been proposed (JP-A-2001-284308).
Further, a cleaning solution having an organic acid compound added to a dispersant and/or a surfactant for removal of metal impurities and particles adsorbed on a substrate having a metal wiring, has been proposed (JP-A-2001-007071).
Further, a cleaning solution containing an aliphatic polycarboxylic acid and a surfactant, with which the contact angle of a substrate having a surface contact angle of at least 70° when water is dropped thereon, is brought to be at most 50°, has also been proposed (JP-A-2003-318150).
Further, a cleaning solution containing an organic acid and a complexing agent, capable of removing particles and metal contamination without corroding a metal wiring, has been proposed (Japanese Patent No. 3219020).
Further, an effective method of planarizing Cu and a Cu alloy to significantly reduce surface defects, has been proposed (JP-A-2001-156029).
Further, a cleaning solution having an alkali or an organic acid added to a specific surfactant and water, to remove fine particles and organic contamination attached to a substrate without corroding the substrate surface, has also been proposed (JP-A-2003-289060).